1. Technical Field
This invention relates to waste management and, more particularly, to a process for the disposal of radioactive waste products contained within spent ion exchange resin beads. Once the radioactive waste products or radionuclides are sealed within the resin beads disposal thereof is facilitated.
2. Background Art
Waste management frequently involves the necessity of disposing of large volumes of materials, some of which may be contaminated with hazardous substances. In nuclear power plants, for example, those utilizing pressurized water reactors and the like, ion exchange resins are used to purify the water in the primary loop of the reactor. After a period of time, the ion exchange resin becomes contaminated with radioactive contaminants and must be disposed of.
Disposal of radioactive wastes, in general, cannot be readily accomplished by using conventional waste disposal techniques because of the relatively long half-lives of certain radioactive elements. The most widely used disposal techniques for radioactive wastes are storage, solidification, and burial. The cost of so disposing of large volumes of radioactive wastes, however, is constantly rising and approaching levels at which volume reduction becomes economically desirable.
Many different methods for disposing of radioactive wastes are known. In U.S. Pat. No. 4,481,134, dated Nov. 6, 1984, microspheres containing nuclear waste can be made by an internal gelation process in which droplets of a chilled feed broth containing the waste, matrix components, urea and hexamethylenetetramine (HMTA) are fed to a heated immiscible gelation liquid, the droplets being gelled as they sink in the liquid by ammonia produced from the decomposition of the HMTA. Thereafter, the microspheres are dried and calcined to arrive at a desired uniform microsphere mass acceptable for subsequent disposal.
In U.S. Pat. No. 4,579,069, dated Apr. 1, 1986, and assigned to the assignee of the present invention, there is disclosed a process for reducing the volume of low-level radioactive wastes by removing the free water contained in the waste by means of spray drying at a temperature sufficient to vaporize the water contained in the waste but insufficient to oxidize the waste or to volatilize any radionuclides present in the waste.
However, to date no process has been found to accomplish volume reduction and make possible the safe disposal of spent ion exchange resin wastes of various types without completely destroying the ion exchange resins or encapsulating same for subsequent disposal.
It is accordingly an object of this invention to provide a process which is capable of reducing the volume and weight of ion exchange resin beads without oxidizing, combusting or interfusing same.
Another object of this invention is to provide a process for sealing radioactive waste products within the resins.
Yet another object of this invention is to provide a cost effective process for safely disposing of bead ion exchange resin wastes.
Other objects and advantages of this invention will become apparent in the course of the following detailed description.